The real race goes by whatever the wx is doing with the boat. Their planning is done by varied wx routing software. Often it is a software NOT yet available commercially - betas of what other sailors might be using. They may also have access to varied and different data sources.

The virtual race uses its own wx data engine that might or might not be related to whatever the real boats are using. And we have no way to know what the boats are EXPERIENCING (which is what actually dictates their set up and their routing decisions). But for VR players this is insignificant, the VR is against other VR racers, not against the real boats.

There is no way a local computer could mimic the algorithm used by VR engine. And they do not let you download their grib files either (or do they?). But some wx routing software might potentially be a better match to the VR algorith than other and some grib sources may actually better match with whatever wx data VR engine is using. (Having) These would give a VR sailor an edge. (Just mind that one can probably BUY more edge getting all the paid options and using them in a smart way).

So to say. Long story and talking about it for hours means nothing once the VR boats take off. The proof of the seaweed pudding ...

At least, when you can see my VR transom you know your boat is headed the right way ;-)

Yes, but we don't speak about VR, which is another Virtual Race engine, We speak about VLM, using qtVLM. There are a lot other virtual sailing engines, for instance SOL (Sail Online), VOR (Virtual Ocean Race), LS (Live Skipper), OV (Ocean Virtual), just to name a few. Some of them are free, most are not.

Using qtVlm together with VLM you get exactly the same grib, interpolation algo for winds and polars, etc. Which is quite normal since it's made by the same team, and VLM/qtVLM are openSource anyway

Yes, I have been updating the Grib each time I check the race, then running a new Routing and then convert to a Route, then optimize & simplify, then check VLM-VBVLM in Route, apply that, then click Autopilot Tab in Route, then Load Automatically the waypoints, then Send. Usually I have it on VBVMG or VMG.

I guess I am not ready yet and must mess around with it more.
I found one of your explanations in another thread Free Routing Software- gtVLM

Quote:

Tore, I just don't understand the question so can you precise a bit what you are trying to do, and especially how you did that in qtVlm?

A bit of explanation anyway:

There are 2 different things in qtVlm, the route and the routing. You can convert from routing to route.

The routing will calculate the best path from arrival to start based on your polar and the grib, using isochrons method. You can force it to avoid certain zones by putting barriers on the map, but this is normally not needed. Before a routing is converted in a route, you can also generate "child-routings", by creating a pivot on one of the isopoints.

Then you convert the routing in a route, and because this new route will contain too many points (one a each isochrone), you can simplify it (this process will remove all POIs that do not improve the ETA, typically aligned POIs are often not needed).

Then eventually you can optimize the route. Basically this process will try to reposition better the POIs, because the routing process only looks at fix step (say one hour), it is understandable that a point might be better placed inbetween 2 isochrons. I want to say that this is perfectionism, and IRL not really useful, because the grib is not precise enough, not to speak about reliability. It is very useful in virtual racing, because the grib is of course 100% accurate in that case.

In the next post Sinbad7 is having difficulty getting a Routing down the East side of Denmark because qtVLM sees the other side as faster.

Ah. I see. This is one of the (rare ) cases where qtVlm needs a bit of help. This is because the west side seems more attractive, and due to the cape that almost blocks the way to the east side, qtVlm decides to not explore that side.

You can force it to do it by blocking the way to the east side, i.e. creating a barrier that will force the program to explore only the east side. Alternatively you could create a pivot point from the closest iso point on the road you want, but creating a barrier is much simpler. In this case (routing in the middle of many obstacles), it is advised (but not compulsory, it actually depends on your polar) to reduce the iso step, for instance to 1/2 hour.

Note that the intermediary POIs are useless, the routing module knows only about start and arrival points, so creating intermediary points is... pointless

Sinbad7 asks....where do I find the tool to create a barrier? Maitai

Quote:

You create 2 POIs (better to make them of a beacon type), right click on one of them, and draw a line (the last option)

Do not have 2 POIs named the same...WP-1 for example, you may be routing towards towards Gibraltar...

Don't use the worst possible polar, oceanExpress. This is a polar from VLM ... this boat is helpless upwind. Choose another, more realistic polar. For instance imoca2008 or pogo850." - (When you are racing in a Virtual Race VLM Boat is checked, the polar for the boat is assigned.)

Next, you have set polar efficiency to 85%, so the poor polar is even worst.

Last thing, if it still does not want to turn the cape, you should move a bit your barrier a bit closer (move the north extremity a bit upper), so qtVlm wont be fooled by the West route.

An option is to quit qtVlm, delete qtVlm.ini, boatAcc.dat and poi.dat and restart. That will make you a clean install with all default options

Barnakiel, you scallywag. Were you just racing the SNSM Imoca 60? What is the name of your boat? Is that the boat you''ll be racing in the Vendee? Just so I know what stern I am following..

;-)

I am not sure I will have time to participate in the virtual race.

If I were, I think running a couple of virtual boats might help you out in the following ways:

- you will be able to RT test route options as they crop up, (e.g picking up different gybe points on passage of a front, or different points of crossing the Equator, going higher with a jib or lower with a kite, etc..),
- you will be able to find which of your software / grib combinations returns results in sych with VR model.

To achieve the latter you run the boats each using a different combination of wx routing software / grib source. Very soon you will find which combo gets awarded extra miles by VR algorithm ...

BTW a good precision: as a rule it's forbidden in VLM to register several boats in the same race. It's what we call OMOROB (One Man One Race One Boat). It's too easy to launch a boat on each weather option to cover all the cases. You have to choose and assume your choice

BTW a good precision: as a rule it's forbidden in VLM to register several boats in the same race. It's what we call OMOROB (One Man One Race One Boat). It's too easy to launch a boat on each weather option to cover all the cases. You have to choose and assume your choice

BTW I know it.

Tell it to Ericsson, ABN AMRO or Telefonica and see what happens.

Rules are set by organizers and whoever gets caught should be DSQ.

Personally I think it is a stupid rule and whoever does not get caught will win.

Within the existing one boat limitation the options can be run consecutively and then measured against their own yardstick. But even so, a plain boat will not win against and optimized one and optimization means you have to spend money. Just like in the real race!

Vendee Questions
1. How is a start handled? - Everyone just does a virtual start on top of one another?
2. With the double waypoint gates. If it is a gate and we run right over the end point of the gate, are we okay?
3. There are two gates:
Ice Gate - You must touch it and go through or not, but you must touch it. You can go through any way.
Classement Gate -Is that Classical? This is a typical gate that you must go through.
4. Do we have port starboard rules etc? Can you run over or through an opponent since this is virtual? Or do we try to keep track of other boats and obey the racing rules?

Vendee Questions
1. How is a start handled? - Everyone just does a virtual start on top of one another?
2. With the double waypoint gates. If it is a gate and we run right over the end point of the gate, are we okay?
3. There are two gates:
Ice Gate - You must touch it and go through or not, but you must touch it. You can go through any way.
Classement Gate -Is that Classical? This is a typical gate that you must go through.
4. Do we have port starboard rules etc? Can you run over or through an opponent since this is virtual? Or do we try to keep track of other boats and obey the racing rules?

1. You must give a boat instruction BEFORE the start. For the time being you boat is at TWA 0 so it won't move otherwise. So for instance you set-up a WP and put the boat in VBVMG and when the time will come it will start moving.
2. If it's not an ice gate you must go through. If you move your mouse over the main gate's point it explains what you must do.
3. Ice gate: You are not obliged to cross them. You must be seen at least once at the North of the gate.
4. No rules concerning collision, starboard, ISAF, etc. You can ignore the other boats.